Use standard tqdm if import ipywidgets fails in notebook

[thomasaarholt]

Using tqdm imported from tqdm.auto in jupyter notebook will fail if ipywidgets is not available.
The current behaviour means that a user with a minimum install of jupyter notebook will not be able to use packages that "naively" utilize tqdm.auto but do not rely on ipywidgets.

This PR lets tqdm.auto revert to using the standard tqdm progress bar if the HTML one is unavailable.

Fixes #1082, #1072.

Test by creating an environment without ipywidgets (ie. conda create -n test notebook and calling the code below:

from tqdm.auto import tqdm as tqdm_auto
for i in tqdm_auto(range(10)):
    pass

I ran into this issue coming from using the Dask tqdm Callback: #1217.

[sourcery-ai]

Sourcery Code Quality Report

❌  Merging this PR will decrease code quality in the affected files by 0.32%.

Quality metrics	Before	After	Change
Complexity	4.00 ⭐	4.00 ⭐	0.00
Method Length	57.00 ⭐	59.00 ⭐	2.00 👎
Working memory	6.00 ⭐	6.00 ⭐	0.00
Quality	80.48% ⭐	80.16% ⭐	-0.32% 👎

Other metrics	Before	After	Change
Lines	28	29	1

Changed files	Quality Before	Quality After	Quality Change
tqdm/autonotebook.py	80.48% ⭐	80.16% ⭐	-0.32% 👎

Here are some functions in these files that still need a tune-up:

File	Function	Complexity	Length	Working Memory	Quality	Recommendation

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[bdice]

@casperdcl Hi! Do you know why this PR's CI appears stuck? (edit: It looks like a maintainer needs to approve it to run.) I'm interested in seeing a solution to issue #1082 and this PR seems like a viable route towards resolving it.

[casperdcl]

Sorry for the massive delay in reviewing. Addressed in v4.63.0 :)

[bdice]

@casperdcl Thank you very much! 👍 tqdm is a lovely package. It brings me joy every time I wrap an iterable in tqdm(...). 😄